Bipolar Disorder Common in Fibromyalgia

New research suggests that just over 25 percent of patients with fibromyalgia also have symptoms of bipolar disorder.

According to Dr. William Wilke from the Cleveland Clinic in Ohio and his colleagues, “the most important finding of our study pertains to the high prevalence of a positive screen for bipolar disorder in patients with fibromyalgia.”

Fibromyalgia is a condition which causes painful muscle, joint and body aches. More common in women, it can also cause fatigue, daytime fatigue, and other symptoms. The causes are unknown and may affect up to five percent of the population. It is thought that depression can at some point affect 90 percent of patients with fibromyalgia. According to the National Institute for Mental Health, depression affects 6.7 million Americans a year, and bipolar disorder affects 2.6 million.

To determine the frequency of bipolar disorder in patients with fibromyalgia, Wilke and his colleagues assessed 128 consecutive fibromyalgia patients who had been newly referred to a rheumatology practice. The patients were asked to complete four different questionnaires, the Mood Disorder Questionnaire (MDQ) for bipolar disorder, the Beck Depression Inventory (BDI), the Epworth Sleepiness Scale (ESS) for daytime sleepiness, and the Fibromyalgia Impact Questionnaire Disability Index (FIQ-DI).

Wilke found that of the fibromyalgia patients, according to the MDQ screen, 25.19 percent of the patients were likely to have bipolar disorder.

Over 78 percent of the fibromyalgia patients were clinically depressed according to the BDI.

Of the patients who tested positive for bipolar disorder, their depression was measured as more severe according to the BDI.

In addition, of the patients who screened positive for depression, almost one third also screened positive for bipolar disorder as well.

Wilke’s team found that, with the exception of severe depression, there were no other clinical clues that suggested depression or bipolar disorders except for the screening questionnaires. “Clinical data and questionnaire instruments other than nonspecific high depression severity failed to identify these patients.”

The authors also point out that certain medications used in treatment of fibromyalgia may have the potential of triggering mania in some bipolar patients. “We urge that bipolar disorder risk be carefully assessed in all patients with fibromyalgia prior to initiation of drug therapy, particularly since norepinephrine serotonin reuptake inhibitors may carry elevated risk for induction of mania.”

Wilke’s results can be seen in the August edition of the journal Bipolar Disorders.